Supporting structure components of an automotive body such as front frame, rear frame, longitudinal members as well as front and rear under floor on the one hand fulfill a static function by absorbing the vehicle weight or the weight of individual vehicle components such as that of the engine. On the other hand, at least some of these components must exhibit a defined deformation behavior in the event of the occurrence of extreme mechanical loads, possibly in the case of a vehicle collision.
The geometrical configuration of individual supporting structure components of an automotive body as well as their mechanical interconnection defines so-called load paths along which the impact energy which occurs in the event of a collision may be diverted in a manner which is as defined as possible. Load paths additionally fulfill the purpose of not only absorbing the collision-induced impact energy but also of keeping the acting forces away from the passenger compartment so that even in the event of serious vehicle collisions, these may fulfill their function as a survival space for the vehicle occupants.
In addition to the mechanical loading requirements to be satisfied, there is a continuous desire to reduce the weight of the automotive body and the motor vehicle as a whole to minimize the fuel consumption.
Known from DE 103 30 167 A1, for example, is a rear floor unit which comprises a rear floor module containing a transverse support upper flange and a frame module containing a transverse support lower flange. Disposed between the transverse support upper flange and the transverse support lower flange is a bracket system which is joined to the upper and lower flange by welding.
Furthermore, the use of light construction materials may be taken into consideration as a weight-saving measure in car body manufacture. Press-hardened components of steel or sheet steel as well as the use of metal sheets having a high fraction of light metals such as magnesium or aluminum or consisting entirely of such comparatively light low-density materials may be considered as suitable light construction materials.
However, as a result of their only moderate corrosion resistance, light construction materials may only be used to a limited extent for exterior components of an automotive body such as front frame, rear frame, longitudinal or transverse members.
Supporting structure components in aluminum or magnesium light-weight construction as well as press-hardened steel sheets for use in the outside region of motor vehicles must therefore always be provided with a protection layer against corrosion. However, the application of a protective layer, possibly by zinc plating, may only be applied very inadequately, for example, for press-hardened steel sheets as a result of thermal stresses in the forming process. In addition, an application of a metal protective layer is always associated with an increase in weight and also an increase in costs.
Thus, for example, DE 10 2006 006 910 B3 describes the use of zinc lamellar-coated steel structural components in chassis frame structures or chassis structures of a motor vehicle formed from a steel/light metal composite. Such a coating comes into consideration in particular for the load-bearing structural components, in particular for those of high or ultrahigh strength steels.
It is at least one object of the present invention to provide an improved supporting structure arrangement, in particular for the rear region of a motor vehicle, which does justice to the mechanical load requirements, which has a comparatively low weight, which may be manufactured in a cost-saving manner, and optionally creates additional installation space. In addition, other objects, desirable features, and characteristics will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background.